The present invention relates to mounting systems. More particularly, the present invention is directed to a fastener system for hollow walls and ceilings.
Most walls and ceilings of newer residential and commercial structures have a hollow cavity construction, that is, there is a hollow space behind the wall. A typical wall has a sheet of material, typically between 1 and 2.54 cm thick, affixed to a suitable frame such as wood or metal framing members, commonly referred to as studs (walls) or joists (ceilings). Forms of sheet material include drywall, wallboard, plasterboard, and gypsum board, sold under the trademark SHEETROCK®.
Various fasteners are available for attaching objects to a wall or ceiling (collectively referred to as wall) at a location other than over the area where a framing member is located. These fasteners can generally be divided into two general types—toggle fasteners and expansion fasteners. Toggle fasteners generally have two components, an anchor or first component has spreading or tilting arms and is inserted with the arms folded into a drilled hole in the wall material, and an activator or second component, typically a screw or pin, is used to cause the anchor's arms to tilt or spread within the hollow space behind the wall to lock the fastener in place on the wall.
Expansion fasteners are generally secured by an increase in their diameter. Some anchors are hammered into a wall or inserted into a pre-drilled hole. An activator such as a pin or screw is forced into a central, cylindrical cavity within the fastener, increasing its diameter. Still other fasteners have tangs which expand to resist pull-out of the fastener.
Toggle and expansion fasteners suffer from significant disadvantages. First, typically, these fastener systems do not have ready-made pins, or tools to insert the pins, to actuate the anchor portion of the fastener. Moreover, tools are required to insert pins and to actuate the anchors.
In addition, difficulty is often encountered in properly tightening the pin/anchor which results in over-torquing the fastener, failure of the wall, or other unacceptable condition. Furthermore, many of these fastening systems are non-removable or are difficult to remove from the wall without leaving a large, unsightly hole. And, expansion fasteners crush the friable drywall material which can limit the grip of the device in the wall.
One other anchor includes a flange that lies flush on the wall and gussets that extend from the flange to provide structural integrity to the flange. A leg section extends rearwardly from the flange and has a point for penetrating the wall. The leg is formed in two section—a fixed section and a rear hinged portion that pivots to engage the inner surface of the wall.
A pin has a head, such as an arrow head that is inserted into an oval opening in the anchor. When the pin is fully inserted into the anchor, it is rotated. The arrow head engages a tip on the rear end of the hinged leg to urge the hinged leg against the inside surface of the wall.
While this hinged anchor functions well in many situations, it is limited in the thickness of the wall into which it is installed. Moreover, it has been found that if the leg cannot rotate 90 degrees to “lock” against the wall inner surface, the shaft may twist and perhaps break as the pin is rotated. This is particularly troublesome in that the pin may not lock in place to lock the anchor. In addition, it has been found that once rotated, the pin often cannot be removed from the anchor. This type of anchor is disclosed in U.S. patent application Ser. No. 11/678,459, filed Feb. 23, 2007.
Accordingly, there is a need for an anchor system that is easily installed in hollow walls, that has pre-formed pins or the like for attaching objects to the wall. Such a system includes an anchor with a hinged leg that locks into place in the wall, with a pin that moves the leg, but that is readily removed from the wall. Desirably, the anchor of such an anchor system is forgiving in that the hinged leg can be at more than or less than 90 degrees and can nevertheless lock to the wall.